Tone Detection in Noise

The following sounds contain a tone that is presented in background noise. The tone is presented at different signal to noise (SNR) ratios. For example, a SNR of +20 means that the tone is 20dB more intense than the background noise. But a SNR of -30dB means that the tone is 30dB less intense than the background noise.

What is the minimum SNR that produces a tone you can hear? Start at the top and work your way down. When you can no longer hear the tone, work your way back up until you can hear the tone again. If you repeat this process many times, you will get a more reliable estimate of your ability to detect tones in background noise.

Questions: if you wanted to cheat this test (and deliberately do either really well or really badly), what would you do? And if you wanted to get a more precise estimate of the tone-in-noise detection threshold, what would you do?

+20 dB SNR